When NASA released this image from their Lunar Orbiter 1 back in 1966, the first photograph ever of the Earth rising above the Moon's surface, it was low resolution but they still amazed the world. This week, they have surprised every space aficionado re-releasing the same image in ultra-high definition. The cool part now is that NASA hasn't used any upscaling or magical infinite zoom-in filter from CSI. Instead, they have created a new technology that uses refurbished analogue machines and a new digital process that fully extracts the information stored in the program's old magnetic tapes, something that was impossible to do in the 60s. Click on the image to watch it in its 3673 x 1740 pixel glory.
The Lunar Orbiter missions included five spacecrafts dedicated to map the entire lunar surface, a task necessary to select the landing sites for Apollo. The first three missions focused on twenty potential landing sites, while the two last ones—which flew high altitude polar orbits—took photographs of 99% of the surface with a resolution that ranged from 60 metres to a stunning 2 metres.
While these probes were not as sophisticated as the HD cameras of the Selene spacecraft developed by the Japanese space agency, the NASA orbiters had a clever imaging system that achieved similar results four decades ago. It included a dual lens camera—one 610 millimetre narrow angle for high resolution and an 80 millimetre wide angle for medium resolution—, a film processor, and a scanner. Both lenses were aligned to expose the same part of the 70 millimetre film roll, so the high resolution image area was centered with the medium resolution area.
This was more complicated that it sounds: Since the spaceship was cruising above the lunar surface, they had to compensate for that motion. Using an electro-optical sensor to measure the distance while a small motor shifted the film so the second exposure exactly matched the first one. After that, the film was processed, scanned, and the information send back to Earth, where it was stored in analogue tapes.
Now, the Lunar Orbiter Image Recovery Project at NASA's Ames Research Centre, is retrieving and analysing all the data stored in those tapes. To do this, first they restored the original tape recorders and 1,500 of these tapes. Then they digitised the data into modern computer, putting it through special software designed to extract all that information to produce the image you are seeing here. Their goal is to do this with every single image lurking inside those tapes, which then will be mapped to standard coordinates and sent to NASA's Jet Propulsion Laboratory in Pasadena, California.
Their objective is not only preserving and enhancing these historical documents, but also provide the scientific community with refreshed information prior to next year's Lunar Reconnaissance Orbiter mission. [NASA]